title: Purification and partial characterization of a macrophage cytotoxin from Pasteurella haemolytica.
abstract: A protein from Pasteurella haemolytica that was highly immunogenic and toxic toward bovine alveolar macrophages was partially purified. When isolated from culture supernatants of P haemolytica serotype 1 or serotype 6, the protein reacted on Ouchterlony immunodiffusion tests with antisera from 12 serotypes of P haemolytica, but did not cross-react with antisera to serotypes of P multocida. This indicated that the protein may be specific for P haemolytica. Bacteria were grown in dialysis culture in a brain-heart infusion and calf-serum growth medium. The protein was isolated from the medium by ultrafiltration and size-exclusion chromatography and has a molecular weight of approximately 150,000 daltons. The protein, which is highly immunogenic and has the characteristics of a virulence factor, is common to all serotypes of P haemolytica, and may be an effective agent for immunization against P haemolytica in cattle.
mesh_terms: D000942:Antigens, Bacterial / Q000276:immunology / Q000302:isolation & purification; D002850:Chromatography, Gel; D003601:Cytotoxicity Tests, Immunologic; D003603:Cytotoxins / Q000276:immunology / Q000302:isolation & purification*; D004591:Electrophoresis, Polyacrylamide Gel; D005779:Immunodiffusion; D008264:Macrophages / Q000032:analysis; D008970:Molecular Weight; D010325:Pasteurella / Q000032:analysis* / Q000276:immunology
chemical_list: D000942:Antigens, Bacterial; D003603:Cytotoxins